[PyQt] PyQt API 2: equivalent of Null QVariant?

TP paratribulations at free.fr
Tue Dec 21 20:06:11 GMT 2010

Phil Thompson wrote:

> The short answer is that you can't. However...
> QVariant::isNull() typically delegates to the enclosed data's isNull()
> method (eg. QString::isNull()). So your example for API v1 will also work
> for API v2.
> It gets a bit more complicated if you are also using the QString v2 API
> because a null QString and an empty QString are both converted to an empty
> unicode object (although None is converted to a null QString when going in
> the other direction). I chose this asymmetric behaviour because QString()
> creates a null QString when often what is really meant is an empty
> QString.

Thanks for your answer.

I have checked that API2 for QVariant works by using isNull() as you said.

But, I cannot use API2 for QString.

This means that I must stick to API1 for QString, at least.

Will API1 support be continued in the next versions of PyQt?
Indeed, detecting NULL is for me very important.



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